U.S. patent number 6,437,699 [Application Number 09/714,214] was granted by the patent office on 2002-08-20 for battery capacity indication circuit and indication method thereof, and battery-operated electronic device and cellular communication terminal apparatus comprising the indication circuit.
This patent grant is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Hideki Hayakawa.
United States Patent |
6,437,699 |
Hayakawa |
August 20, 2002 |
Battery capacity indication circuit and indication method thereof,
and battery-operated electronic device and cellular communication
terminal apparatus comprising the indication circuit
Abstract
When a remaining capacity of a battery is displayed by remaining
capacity display control means, operation state discrimination
function discriminates an operation state of an apparatus and also
discriminates whether battery output voltage Vout is greater than
discrimination value Vp when the apparatus is in reception
indication operation. If the battery output voltage Vout is greater
than the discrimination value Vp, remaining capacity of the battery
corresponding to the battery output voltage Vout in a standby state
immediately before the start of the reception indication operation
is displayed on LCD. If the battery output voltage Vout is equal to
or smaller than the discrimination value Vp, the remaining capacity
of the battery corresponding to the battery output voltage Vout of
this time is displayed as it is on the LCD.
Inventors: |
Hayakawa; Hideki (Hachioji,
JP) |
Assignee: |
Kabushiki Kaisha Toshiba
(Kawasaki, JP)
|
Family
ID: |
18230321 |
Appl.
No.: |
09/714,214 |
Filed: |
November 17, 2000 |
Foreign Application Priority Data
|
|
|
|
|
Nov 19, 1999 [JP] |
|
|
11-330230 |
|
Current U.S.
Class: |
340/636.13;
340/660; 340/691.6; 340/693.2; 455/573; 455/572; 340/693.3;
455/343.5; 340/311.2; 340/693.1 |
Current CPC
Class: |
H04W
52/0261 (20130101); H04W 52/0277 (20130101); H04M
1/724 (20210101); H02J 7/0048 (20200101); H02J
7/0047 (20130101); G01R 31/3646 (20190101); Y02D
30/70 (20200801) |
Current International
Class: |
H04B
1/16 (20060101); H04M 1/73 (20060101); H02J
7/00 (20060101); H04M 1/72 (20060101); G01R
31/36 (20060101); G08B 021/00 () |
Field of
Search: |
;340/636,660,661,662,663,664,691.6,693.1,693.2,693.3,693.4,311.1
;455/67.1,572,573 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hofsass; Jeffery
Assistant Examiner: Previl; Daniel
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier
& Neustadt, P.C.
Claims
What is claimed is:
1. A battery capacity indication circuit for generating and
indicating information about a capacity of a battery supplying
power to an electronic circuit, comprising: means for detecting and
keeping an output value of the battery in a state where the
electronic circuit is operated by power supplied from the battery;
means for discriminating whether said electronic circuit is in a
first operation state of consuming power smaller than a
predetermined value or a second operation state of consuming power
greater than the predetermined value in a state where the
electronic circuit is operated by power supplied from the battery;
means for comparing the output value of the battery detected in
said second operation state with a predetermined threshold value if
it is discriminated that said electronic circuit is in the second
operation state; and means for generating and indicating
information about the capacity of said battery on the basis of the
output value of said battery detected and kept in said first
operation state before said electronic circuit becomes in said
second operation state, if it is determined that the output value
of said battery is equal to or greater than the threshold
value.
2. A battery capacity indication circuit according to claim 1,
wherein said indication means further comprises a function of
generating and indicating information about the capacity of said
battery on the basis of a current output value thereof, when it is
discriminated as a result of the comparison executed by said
comparison means that the output value of said battery is smaller
than the threshold value.
3. A battery capacity indication circuit according to claim 1,
wherein said indication means generates and indicates information
about a remaining capacity of said battery on the basis of the
output value thereof detected by said detection means.
4. A battery capacity indication circuit according to claim 1,
wherein said indication means generates and indicates information
about power consumption of said battery on the basis of the output
value thereof detected by said detection means.
5. A battery capacity indication circuit according to claim 1,
wherein said indication means obtains a remaining time to operate
said electronic circuit on the basis of a current remaining
capacity of said battery, on the basis of the output value of said
battery detected by said detection means, discharging
characteristics of said battery and an average value of the power
consumption of said electronic circuit, and indicates information
representing the remaining time.
6. A battery capacity indication circuit according to claim 1,
wherein said indication means obtains a remaining number of times
at which said electronic circuit repeats a determined operation,
from a remaining capacity of said battery, on the basis of a
current remaining capacity of said battery, on the basis of the
output value of said battery detected by said detection means,
discharging characteristics of said battery and an average value of
the power consumption of said electronic circuit, and indicates
information representing the remaining number of times.
7. A battery capacity indication circuit according to claim 1,
wherein said discrimination means discriminates whether said
electronic device is in a standby state or other operation
state.
8. A battery-operated electronic device having a battery as a power
supply, for supplying an output of said battery to an electronic
circuit and selectively executing a plurality of kinds of
determined operations, said electronic device comprising: means for
detecting and keeping an output value of said battery in a state
where the electronic circuit is operated by power supplied from the
battery, means for discriminating whether said electronic circuit
is in a first operation state of consuming power smaller than a
predetermined value or a second operation state of consuming power
greater than the predetermined value in a state where the
electronic circuit is operated by power supplied from the battery;
means for comparing the output value of the battery in said second
operation state with a predetermined threshold value if it is
discriminated that said electronic circuit is in the second
operation state, and means for generating and indicating
information about the capacity of said battery on the basis of the
output value of said battery detected and kept in said first
operation state before said electronic circuit becomes in said
second operation state, if it is determined that the output value
of said battery is equal to or greater than the threshold
value.
9. A battery-operated electronic device according to claim 8,
wherein said indication means further comprises a function of
generating and indicating information about the capacity of said
battery on the basis of a current output value thereof, when it is
discriminated as a result of the comparison executed by said
comparison means that the output value of said battery is smaller
than the threshold value.
10. A battery-operated electronic device according to claim 8,
wherein said indication means generates and indicates information
about a remaining capacity of said battery on the basis of the
output value thereof detected by said detection means.
11. A battery-operated electronic device according to claim 8,
wherein said indication means generates and indicates information
about power consumption of said battery on the basis of the output
value thereof detected by said detection means.
12. A battery-operated electronic device according to claim 8,
wherein said indication means obtains a remaining time to operate
said electronic circuit on the basis of a current remaining
capacity of said battery, on the basis of the output value of said
battery detected by said detection means, discharging
characteristics of said battery and an average value of the power
consumption of said electronic circuit, and indicates information
representing the remaining time.
13. A battery-operated electronic device according to claim 8,
wherein said indication means obtains a remaining number of times
at which said electronic circuit repeats a determined operation,
from a remaining capacity of said battery, on the basis of a
current remaining capacity of said battery, on the basis of the
output value of said battery detected by said detection means,
discharging characteristics of said battery and an average value of
the power consumption of said electronic circuit, and indicates
information representing the remaining number of times.
14. A battery-operated electronic device according to claim 8,
wherein said discrimination means discriminates whether said
electronic device is in a standby state or other operation
state.
15. A cellular communication terminal apparatus having a battery as
a power supply, for supplying an output of said battery to an
electronic circuit and selectively executing a plurality of kinds
of operations about cellular communication, said terminal apparatus
comprising means for detecting and keeping an output value of said
battery in a state where the electronic circuit is operated by
power supplied from the battery, means for discriminating whether
said electronic circuit is in a first operation state of consuming
power smaller than a predetermined value or a second operation
state at consummg power greater than the predetermined value in a
state where the electronic circuit is operated by power supplied
from the battery; means for comparing the output value of the
battery detected in said second operation state with a
predetermined threshold value if it is discriminated that said
electronic circuit is in the second operation state; and means for
generating and indicating information about the capacity of said
battery on the basis of the output value of said battery detected
and kept in said first operation state before said electronic
circuit becomes in said second operation state, if it is determined
that the output value of said battery is equal to or greater than
the threshold value.
16. A cellular communication terminal apparatus according to claim
15, wherein said indication means further comprises a function of
generating and indicating information about the capacity of said
battery on the basis of a current output value thereof, when it is
discriminated as a result of the comparison executed by said
comparison means that the output value of said battery is smaller
than the threshold value.
17. A cellular communication terminal apparatus according to claim
15, wherein said indication means generates and indicates
information about a remaining capacity of said battery on the basis
of the output value thereof detected by said detection means.
18. A cellular communication terminal apparatus according to claim
15, wherein said indication means generates and indicates
information about power consumption of said battery on the basis of
the output value thereof detected by said detection means.
19. A cellular communication terminal apparatus according to claim
15, wherein said indication means obtains a remaining time to
operate said electronic circuit on the basis of a current remaining
capacity of said battery, on the basis of the output value of said
battery detected by said detection means, discharging
characteristics of said battery and an average value of the power
consumption of said electronic circuit, and indicates information
representing the remaining time.
20. A cellular communication terminal apparatus according to claim
15, wherein said indication means obtains a remaining number of
times at which said electronic circuit repeats a determined
operation, from a remaining capacity of said battery, on the basis
of a current remaining capacity of said battery, on the basis of
the output value of said battery detected by said detection means,
discharging characteristics of said battery and an average value of
the power consumption of said electronic circuit, and indicates
information representing the remaining number of times.
21. A cellular communication terminal apparatus according to claim
15, wherein said discrimination means discriminates whether said
electronic device is in a standby state or other operation
state.
22. A cellular communication terminal apparatus according to claim
15, wherein said discrimination means discriminates whether said
electronic device is in the standby state, a communication state or
an operation state of executing at least one of generation of
ringing, generation of vibration and putting on a display
light.
23. A battery indication method of generating and indicating
information about a capacity of a battery supplying power to an
electronic circuit, said method comprising: a detection step of
detecting and keeping an output value of said battery in a state
where the electronic circuit is operated by power supplied from the
battery; a discrimination step of discriminating whether said
electronic circuit is in a first operation state of consuming power
smaller than a predetermined value or a second operation state of
consuming power greater than the predetermined, value in a state
where the electronic circuit is operated by power supplied from the
battery; a comparison step of comparing the output value of the
battery detected in said second operation state with a
predetermined threshold value if it is discriminated that said
electronic circuit is in the second operation state; and an
indication step of generating and indicating information about the
capacity of said battery on the basis of the output value of said
battery detected and kept in said first operation state before said
electronic circuit becomes in said second operation state, if it is
determined that the output value of said battery is equal to or
greater than the threshold value.
24. A battery indication method according to claim 23, further
comprising a second indication step of generating and indicating
information about the capacity of said battery on the basis of a
current output value thereof, when it is discriminated as a result
of the comparison executed at said comparison step that the output
value of said battery is smaller than the threshold value.
25. A battery capacity indication circuit for indicating
information about a remaining battery capacity, the battery
supplying power to an electronic circuit, said circuit comprising:
means for detecting and keeping an output value of said battery in
a state where the electronic circuit is operated by power supplied
from the battery; means for discriminating whether or not said
electronic circuit is in a predetermined operation state in a state
where the electronic circuit is operated by power supplied from the
battery; means for comparing the output value of the battery
detected in said predetermined operation state with a predetermined
threshold value if it is determined that said electronic circuit is
in the predetermined operation state; and means for generating and
indicating information about the remaining capacity of said battery
on the basis of the output value which is detected and kept before
said electronic circuit becomes in said predetermined operation
state, if it is determined that the output value of said battery is
equal to or greater than the threshold value.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority
from the prior Japanese Patent Application No. 11-330230, filed
Nov. 19, 1999, the entire contents of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
This invention relates to a battery capacity indication circuit and
an indication method thereof for use in an electronic device having
a battery as a power supply, for example, a cellular communication
terminal apparatus such as a cellular telephone or the like, a
portable personal computer, a PDA (Personal Digital Assistants), a
portable audio player, and a video camera, to detect an output of
the battery and provide information relating to the capacity
thereof and, more particularly, to a battery-operated electronic
device and a cellular communication terminal apparatus comprising
the battery capacity indication circuit.
Recently, various cellular communication terminal apparatuses such
as cellular telephones, PDA and the like have been used in
accordance with the development of the communications technology
and the variety of demand on the cellular communication.
Incidentally, the terminal apparatus of this kind has a battery as
its power supply. For this reason, the battery needs to be
constantly charged or exchanged to the other. Thus a battery
capacity indication circuit is generally provided in the cellular
communication terminal apparatus. This circuit discriminates the
remaining capacity of the battery on the basis of the output
voltage thereof and displays it on a display unit. Therefore, the
user can confirm the remaining capacity of the battery by this
display unit, at any time, during the operation of the terminal
apparatus.
However, the conventional battery capacity indication circuit of
this kind has the following problem that should be solved. That is,
current consumption of the apparatus is temporarily increased when
the apparatus becomes in a specific operation state, for example,
at the time of outputting a ringing tone accompanying an incoming
call, operating a vibrator, turning on a back light of the liquid
crystal display, and the like. Thus, the battery output shows the
voltage drop. A current apparatus has a battery of small capacity
for downsizing and weight reduction. Therefore, the voltage drop of
the battery output cannot be neglected.
In the conventional remaining capacity indication circuit, however,
the detected value is always displayed as it is without considering
the voltage drop of the battery output. For this reason, an
erroneous remaining capacity lower than an actual value is
displayed in the above-described specific operation state. In this
case, it is not preferable that the user may commit an erroneous
operation of turning off the power supply of the apparatus by
judging that the battery would be exhausted soon, though the
apparatus can be still operated.
On the other hand, canceling the detection of the battery voltage
not to display the remaining capacity in the above-described
specific operation state has been proposed to prevent such
inconvenience. According to this manner, however, the user cannot
confirm the remaining capacity of the battery during the operations
in the specific operation state. For this reason, even if the
remaining capacity of the battery is reduced and the battery
voltage is lower than a predetermined value such that the
power-down suddenly occurs, the user cannot confirm the reason
therefor.
BRIEF SUMMARY OF THE INVENTION
This invention is accomplished in consideration of the
above-described circumstances. The object of this invention is to
provide a battery capacity indication circuit and indication method
thereof capable of exactly indicating a battery capacity even if
the battery output is temporarily varied in a specific operation
state of the electronic circuit, and also provide a
battery-operated electronic device and cellular communication
terminal apparatus comprising the indication circuit.
To achieve the object, a battery capacity indication circuit
according to this invention comprises a function of detecting and
keeping an output value of the battery, a function of
discriminating whether the electronic circuit is in a first
operation state of consuming the power of smaller than a
predetermined value or a second operation state of consuming the
power of greater than the predetermined value, a function of
comparing the output value of the battery detected by the detection
function with a predetermined threshold value if it is
discriminated by the discrimination function that the electronic
circuit is in the second operation state, and a function about the
battery capacity. The indication function generates and indicates
information about the capacity of the battery on the basis of the
output value of the battery detected by the detection function in
the first operation state before the electronic circuit becomes in
the second operation state, if it is determined by the comparison
function that the output value of the battery is equal to or
greater than the threshold value.
Therefore, according to this invention, even in a case where a
specific operation of consuming comparatively large current, such
as outputting a reception ringing, vibrating operation of the
vibrator, putting on the display backlight or the like, is executed
in the electronic circuit, if the output value of the battery is
still very great, the remaining capacity of the battery detected in
a standby state immediately before the specific operation or in a
communication state is displayed without receiving influence of
temporary voltage drop of the battery voltage caused by the
specific operation. For this reason, inconvenience of erroneously
displaying the remaining capacity of the battery smaller than the
actual value can be prevented, and thereby the user can exactly
recognize the remaining capacity of the battery.
In addition, the battery capacity indication circuit according to
this invention is characterized in that the indication function
further comprises a function of generating and indicating
information about the capacity of the battery on the basis of a
current output value thereof, when it is discriminated as a result
of the comparison executed by the comparison means that the output
value of the battery is smaller than the threshold value.
Therefore, according to this invention, even in a specific
operation state, the user can confirm that the remaining capacity
of the battery is being exhausted and can thereby properly judge
whether or not he can continue the subsequent operations. In
addition, even if the supply of the power is suddenly interrupted
during the specific operation, the user can clearly understand the
reason.
A plurality of specific examples of the indication function can be
conceived as follows.
The first structure is to generate and indicate the information
representing the remaining capacity of the battery on the basis of
the output value thereof detected by the detection function.
The second structure is to generate and indicate the information
representing the power consumption of the battery on the basis of
the output value thereof detected by the detection function.
The third structure is to obtain the remaining capacity of the
battery on the basis of the output value thereof detected by the
detection function, obtain the remaining time to operate the
electric circuit from the remaining capacity, and indicate the
information representing the remaining time.
The fourth structure is to obtain the remaining capacity of the
battery on the basis of the output value thereof detected by the
detection function, obtain the remaining number of times to operate
the electric circuit from the remaining capacity, and indicate the
information representing the remaining number of times.
Further, the information can be displayed by selecting one or more
of the first to fourth structures, in accordance with the user's
selecting operation.
Additional objects and advantages of the invention will be set
forth in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate presently preferred
embodiments of the invention, and together with the general
description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
FIG. 1 is a block diagram showing a cellular communication terminal
apparatus comprising a remaining capacity indication circuit
according to the embodiment of the present invention;
FIG. 2 is a flow chart showing steps and contents of remaining
capacity display operation executed by a control circuit of the
apparatus shown in FIG. 1;
FIG. 3 is a graph showing an example of the discharging
characteristics of the battery and the display of the battery
remaining capacity;
FIG. 4 is a graph explaining the battery display operation in a
case where battery output voltage Vout is higher than
discrimination value Vp;
FIG. 5 is a graph explaining the battery display operation in a
case where battery output voltage Vout is equal to or lower than
discrimination value Vp;
FIGS. 6A, 6B and 6C are diagrams showing display examples of the
remaining capacity; and
FIG. 7 is a flow chart showing the contents of a remaining time
displaying process in a remaining capacity indication circuit
according to the other embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a block diagram showing a cellular communication terminal
apparatus comprising a battery capacity indication circuit
according to the embodiment of the present invention.
A radio carrier signal transmitted from a base station (not shown)
via a radio channel is input to a receiver (RX) 3 via an antenna 1
and a duplexer (DUP) 2. In the receiver 3, the radio carrier signal
is synthesized with a receiving local oscillation signal that is
output from a frequency synthesizer (SYN) 4 and converted into a
receiving intermediate frequency signal. The receiving intermediate
frequency signal is subjected to the sampling in an A/D converter 7
and input to a digital demodulation circuit (DEM) 6. In the digital
demodulation circuit 6, the receiving intermediate frequency signal
is subjected to the frame synchronization and bit synchronization
and then digitally demodulated.
A received signal strength detector is provided in the receiver 3.
A received signal strength RCS of the radio carrier signal detected
by the received signal strength detector is input to a control
circuit (CONT) 20. The synchronization information obtained by the
frame synchronization and bit synchronization is also input to the
control circuit 20.
The digital demodulation signal that is output from the digital
demodulation circuit 6 includes a digital speech signal and a
digital control signal. The digital control signal is supplied to
the control circuit 20 and identified. The digital speech signal is
subjected to error correction and deinterleaving in a channel
decoder (CH-DEC) 8. The digital speech signal subjected to the
error correction and deinterleaving is subjected to speech decoding
in a speech decoder (SP-DEC) 9, converted to an analog speech
signal by a D/A converter 10, supplied to a loud-speaker 11 and
finally output from the loud-speaker 11.
On the other hand, a speech signal which is input by a microphone
12 is sampled by an A/D converter 13, input to a speech encoder
(SP-COD) 15 via an echo canceller (AEC) 14, and subjected to speech
encoding in the speech encoder 15. The encoded digital speech
signal obtained from the speech encoding is subjected to error
correction and interleaving in a channel encoder (CH-COD) 16
together with the digital control signal that is output from the
control circuit 20, and is input to a digital modulation circuit
(MOD) 18. In the digital modulation circuit 18, a modulation signal
corresponding to the encoded digital speech signal is generated.
The modulation signal is converted into an analog signal in a D/A
converter 17 and input to a transmitter (TX) 5. In the transmitter
5, the modulation signal is synthesized with a transmission local
oscillation signal that is output from the frequency synthesizer 4
and converted into a transmission radio frequency signal, which is
amplified by a transmission power amplifier. The radio frequency
signal output from the transmitter 5 is transmitted from the
antenna 1 to a base station (not shown) via the duplexer 2.
The cellular communication terminal apparatus is composed of an
apparatus main body unit MS and a battery pack unit BP detachably
mounted on the main body MS via a connector. A rechargeable battery
23 constituted by, for example, a lithium ion battery is contained
in the battery pack unit BP. Output voltage Vout of the battery 23
is supplied to a power supply circuit (POW) 24 of the apparatus
main body MS via a connector. The power supply circuit 24 generates
a predetermined operation voltage Vcc on the basis of the output
voltage Vout of the battery and supplies it to each circuit in the
apparatus main body MS. The output voltage Vout of the battery 23
is also input to an A/D converter 25 serving as a voltage detection
circuit. The A/D converter 25 inputs a digital value representing a
value of the battery output voltage Vout to the control circuit
20.
Reference numeral 21 denotes a key input section (KEY), which
includes a send key, an end key, a digit keys and various function
keys. Reference numeral 22 denotes a liquid crystal display (LCD),
which displays the dial information of a communication partner,
operation state of the apparatus, and the like.
The control circuit 20 comprises, for example, a microcomputer as a
main control unit. The control circuit 20 has an operation state
discrimination function 20a and a remaining capacity display
control function 20b as new functions associated with this
invention, in addition to general control functions for the radio
connection control, communication control and the like.
The operation state discrimination function 20a discriminates
whether the operation state of the apparatus is a specific
operation state in which the current consumption is equal to or
higher than a predetermined value, such as the output of the
ringing tone, operation of the vibrator or turning on the backlight
of the LCD 22, or a general operation state in which the current
consumption is smaller than a predetermined value, such as a
standby state, a communication state or the like.
The remaining capacity display control function 20b generates
remaining capacity display information in accordance with the
discrimination result of the operation state discrimination
function 20a at the time of displaying the remaining capacity of
the battery 23. That is, when the operation state is the general
operation state, the remaining capacity display control function
20b generates remaining capacity display information in accordance
with the battery output voltage value Vout currently detected by
the A/D converter 25 and the discharging characteristics of the
battery and the information is displayed on the LCD 22.
When the operation state is a specific operation state, the battery
output voltage value Vout is compared with a predetermined
discrimination value Vp. If the battery output voltage value Vout
is higher than the predetermined discrimination value Vp, the
remaining capacity display information is generated on the basis of
the battery output voltage value Vout in the standby state obtained
immediately before the apparatus becomes in a specific operation
state. The generated information is displayed on the LCD 22. On the
other hand, if the battery output voltage value Vout is smaller
than the predetermined discrimination value Vp, the remaining
capacity display information is generated on the basis of the
battery output voltage value Vout detected by the A/D converter 25
and the information is displayed on the LCD 22.
Next, the remaining capacity display operation in the
above-constituted apparatus will be explained. FIG. 2 is a flow
chart showing steps and contents of the remaining capacity display
operation executed by the control circuit 20.
When the apparatus is in use, the control circuit 20 discriminates
whether or not the battery output voltage Vout input from the A/D
converter 25 is lower than a minimum operation guarantee voltage
value Vmin of each circuit inside the apparatus, at step 2a. If the
battery output voltage Vout is lower than a minimum operation
guarantee voltage value Vmin, the operation shifts to step 2i at
which an alarm indicating that the battery is almost exhausted is
generated. After that, supply of the operation voltage Vcc for each
circuit inside the apparatus is interrupted at step 2j.
If the battery output voltage Vout is higher than a minimum
operation guarantee voltage value Vmin, the operation shifts to
step 2b at which the operation state of the apparatus is
discriminated. That is, the operation state discrimination function
20a discriminates whether the current operation state of the
apparatus is a specific operation state in which the current
consumption is equal to or higher than a predetermined value, such
as the output of ringing tone operation of the vibrator or turning
on the backlight of the LCD 22, or a general operation state in
which the current consumption is smaller than a predetermined
value, such as a standby state, a communication state or the
like.
If the operation state of the apparatus is the general operation
state as a result of the discrimination, the remaining capacity
display information is generated on the basis of the current
battery output voltage Vout at step 2c, and the information is
supplied to the LCD 22 and displayed thereon. Passage of a certain
time is monitored at step 2e. After a certain time has passed, the
operation returns to step 2a to input new battery output voltage
Vout from the A/D converter 25, and the above control is repeated.
The certain time is set to be a sampling cycle of the battery
output voltage Vout.
It is assumed that the operation state of the apparatus is a
specific operation state in which the ringing tone is generated or
the vibrator is operated in accordance wit the incoming call. In
this case, the control circuit 20 shifts to step 2f and
discriminates whether or not the battery output voltage Vout of
this time is higher than the preset discrimination value Vp. If the
battery output voltage Vout is higher than the discrimination value
Vp, the remaining capacity display information is generated on the
basis of the battery output voltage value Vout obtained in the
standby state immediately before the apparatus becomes in the above
certain operation state and the information is displayed on the LCD
22.
For example, the battery 23 has the discharging characteristics as
shown in FIG. 3 now. The remaining capacity of the battery is
indicated by "LEVEL 3" when the battery output voltage Vout is
higher than threshold value L2, "LEVEL 2" when the battery output
voltage Vout is lower than threshold value L2 and higher than
threshold value L1, and "LEVEL 1" when the battery output voltage
Vout is lower than threshold value L1.
It is assumed that with these characteristics, for example, an
incoming call occurs in a state in which the remaining capacity of
the battery is at "LEVEL 3" and that in accordance with the
incoming call the ringing tone is generated or the vibrator is
operated. In this case, the battery output voltage Vout is
temporarily lowered, causing the voltage drop as shown in, for
example, an enlarged view of FIG. 4, during the reception
indicating operation. If the remaining capacity of the battery is
indicated in this state by employing the battery output voltage
Vout as it is, similarly to the conventional control method, the
battery output voltage Vout becomes lower than the threshold value
L2 in a section represented by E in FIG. 4, during the reception
indicating operation. Therefore, "LEVEL 2" is displayed as the
remaining capacity display information. That is, the remaining
capacity of the battery is erroneously displayed by the influence
of the temporary voltage drop of the battery output voltage value
Vout.
On the other hand, in a case where the display of the battery is
controlled by the control circuit 20 of this embodiment, the
battery output voltage Vout is higher than the discrimination value
Vp at this time. During the reception indicating operation, the
remaining capacity display information is therefore generated on
the basis of the battery output voltage Vout at the standby time
immediately before the start of this period, and the information is
displayed on the LCD 22. That is, "LEVEL 3" is displayed without
receiving the influence of the temporary voltage drop of the
battery output voltage Vout. For this reason, the user of the
apparatus can always recognize the exact remaining capacity of the
battery even during the reception indicating operation.
If the battery output voltage Vout is lower than the discrimination
value Vp, the control circuit 20 shifts to step 2c, generates the
remaining capacity display information on the basis of the battery
output voltage Vout of this time, and supplies the information and
allows the information to be displayed thereon.
It is assumed, for example, that the reception indicating operation
is started while the battery output voltage Vout gets close to the
threshold value L1 as shown in FIG. 5, and that the battery output
voltage Vout becomes lower than the threshold value L1 and reaches
the minimum operation guarantee voltage value Vmin during the
reception indicating operation. In this case, the user cannot know
anything about the remaining capacity of the battery according to
the system of stopping the remaining capacity display during the
reception indicating operation similarly to the prior art.
However, if the display control is executed by the control circuit
20 of this embodiment, the remaining capacity display information
generated on the basis of the battery output voltage Vout in a
standby state immediately before the start of the reception
indicating operation is displayed on the LCD 22, in the same manner
as that shown in FIG. 4, in a section in which the battery output
voltage Vout is higher than the discrimination value Vp. On the
other hand, the remaining capacity display information is generated
on the basis of the battery output voltage Vout of this time and
displayed on the LCD 22 in a section in which the battery output
voltage Vout is lower than the discrimination value Vp, i.e. in a
section as represented by E2 of FIG. 5. That is, "LEVEL 2" is
displayed in the section in which the battery output voltage Vout
is higher than the discrimination value Vp while "LEVEL 1" is
displayed in section E2 in which the battery output voltage Vout is
lower than the discrimination value Vp.
For this reason, the user can confirm the remaining capacity of the
battery even during the reception indicating operation. In
addition, the remaining capacity of the battery obtained in the
standby state immediately before the start of the remaining
capacity display information is not displayed, but the remaining
capacity of the battery corresponding to the battery output voltage
Vout of this time is displayed in section E2 in which the battery
output voltage Vout is lower than the discrimination value Vp and
is almost exhausted. Therefore, the user can exactly recognize the
small remaining capacity of the battery.
FIGS. 6A to 6C show examples of display results of the remaining
capacity display information. FIG. 6A shows an example of "LEVEL
3", FIG. 6B shows an example of "LEVEL 2", and FIG. 6C shows an
example of "LEVEL 1".
In addition, when the battery output voltage Vout has just become
lower than the minimum operation guarantee voltage value Vmin,
during the reception indicating operation, the low voltage alarm is
generated at step 2i. After that, the supply of the power is
interrupted at step 2j.
Thus, in this embodiment, the operation state of the apparatus is
discriminated when the remaining capacity of the battery is
displayed, and it is discriminated whether the battery output
voltage Vout is higher or lower than discrimination value Vp when
the apparatus is in the reception indicating operation. If the
battery output voltage Vout is higher than discrimination value Vp,
the remaining capacity of the battery corresponding to the battery
output voltage Vout in the standby state immediately before the
start of the reception indicating operation is displayed on the LCD
22. If the battery output voltage Vout is lower than discrimination
value Vp, the remaining capacity of the battery corresponding to
the battery output voltage Vout of this time is displayed as it is
on the LCD 22.
Therefore, according to this embodiment, even when a specific
operation of a large current consumption such as the reception
indicating operation is being executed, if the battery output
voltage Vout is higher than the discrimination value Vp, the
remaining capacity of the battery in the standby state is displayed
without receiving the influence of the temporary voltage drop of
the battery output voltage Vout caused by the above specific
operation. For this reason, inconvenience of erroneously displaying
the remaining capacity of the battery smaller than the actual value
can be prevented, and therefore the user can exactly recognize the
remaining capacity of the battery.
If the battery output voltage Vout is lowered to the value near the
minimum operation guarantee voltage value Vmin, the remaining
capacity of the battery corresponding to the battery output voltage
Vout detected in a specific operation state is displayed as it is.
For this reason, even in a specific operation state, the user can
confirm that the remaining capacity of the battery is being
exhausted and can thereby properly judge whether or not he can
continue the subsequent operations. In addition, the remaining
capacity of the battery obtained in the standby state immediately
before the start of the remaining capacity display information is
not displayed, but the remaining capacity of the battery
corresponding to the battery output voltage Vout of this time is
displayed in the section where the battery output voltage Vout is
lower than the discrimination value Vp and is almost exhausted.
Therefore, the user can exactly recognize the small remaining
capacity of the battery.
The present invention is not limited to the above-described
embodiment. For example, in the above embodiment, the reception
indicating operation has been explained as the specific operation
state in which a large current is consumed. However, the present
invention can also be applied even in a state of putting on a
backlight for the LCD 22.
Further, a case where the remaining capacity of the battery is
always displayed during the use of the apparatus has been explained
in the above embodiment. However, the present invention can also be
applied to a case of displaying the remaining capacity of the
battery when the user operates displaying the remaining capacity of
the battery.
Moreover, a case of displaying the remaining capacity of the
battery at three stages from "LEVEL 3" to "LEVEL 1" has been
explained in the above embodiment. However, the remaining capacity
of the battery may be displayed at four or more stages. Otherwise,
the remaining capacity of the battery may be displayed at no
stage.
Moreover, a case of displaying the remaining capacity of the
battery has been explained in the above embodiment. However, the
consumption of the battery may be displayed. The consumption of the
battery can be obtained on the basis of the output voltage Vout of
the battery and the discharging characteristics of the battery,
similarly to the remaining capacity of the battery.
Besides the remaining capacity of the battery and the consumption
of the battery, other information concerning the capacity of the
battery may be displayed. For example, a remaining time in which
the apparatus can be operated with the remaining capacity of the
battery may be obtained and displayed.
FIG. 7 is a flow chart showing the contents of the displaying
process in this remaining time. When the control circuit 20 has
ended the discrimination at step 2b or 2f shown in FIG. 2, the
control circuit 20 calculates a presumed value of the remaining
time to use the apparatus on the basis of the output voltage Vout
of the battery, and preliminarily stored discharging
characteristics of the battery and average power consumption value
of the apparatus, at step 7a. The presumed value of the remaining
time is displayed on the LCD 22 at step 7b. As for an example of
display, the value of the remaining time may be displayed as a
number or may be converted into a position of a hand of a
clock.
In addition, if the apparatus, such as a digital camera or the
like, repeats a determined short operation (for example, picking up
still images), the remaining number of operations that can be
executed with the remaining capacity of the battery may be obtained
and displayed.
Moreover, the remaining capacity of the battery, the remaining time
to use the apparatus, and the like are displayed on the LCD 22 in
the above-described embodiments. For example, however, the speech
systemization technique may be employed to generate a speech
message indicating the remaining capacity of the battery, the
remaining time to use the apparatus, and the like and output the
speech message from the loud-speaker 11 or a sounder for outputting
the ringing.
Moreover, a case of providing the battery indicating circuit in the
cellular communication terminal apparatus has been explained in the
above-described embodiments. However, the battery indicating
circuit cannot be applied only to the cellular communication
terminal apparatus, but to portable personal computers, portable
radio sets, portable CD or MD players, video cameras and other
battery-operated electronic devices.
The steps and contents of the battery indication control,
indicating manner, discrimination value Vp, kinds of the battery,
structure of the electronic circuit and electronic device, and the
like can be variously modified in a range which does not exceed the
gist of this invention.
Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects
is not limited to the specific details and representative
embodiments shown and described herein. Accordingly, various
modifications may be made without departing from the spirit or
scope of the general inventive concept as defined by the appended
claims and their equivalents.
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